622 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 43. 



second to fifth plates this comb covers a second parallel comb of 

 smaller spines, as in OtenopTioraster, and some species of Persepho- 

 naster. Proximally the first comb consists of about 5 larger spines, 

 the third from the upper the longest; and, forming a continuous 

 series with these on the distal margin of the actinal surface, 3 or 4 

 smaller and more delicate ones. Beyond the eighth or ninth plate 

 only the lateral comb remains and consists of 5 or 4 spines, dimin- 

 ishing to 3 or 4 at the very tip of ray. Owing to the tumidity of the 

 outer end of the plate, 2 or 3 of these spines are dorsal in position 

 and are pressed against the sloping side wall of the superomarginals. 

 The second comb is confined strictly to the first 4 or 5 plates, and to 

 the outer end, forming a parallel series between the base of the regu- 

 lar comb and the distal edge of the plate. 



DIPSACASTER DIAPHORUS, new species. 



vSimilar in form to D. sladeni but differing in having short, thick, 

 clavate, or subterete, thorny paxillar spinelets, more numerous 

 adambulacral spinules, a small madreporic body, and less conspicuous 

 marginal spinules; all the shorter spines and spinelets thorny; 

 paxillas wdth 20 to 25 spinelets; furrow spines 8 or 9, very slender, 

 pointed, slightly compressed; subambulacral spinules 15 to 20 

 arrangeed in series, or forming a sort of rosette-like group on the 

 convex surface of the plate; madreporic body small. Rays rather 

 slender, disk large, interbrachia abruptly rounded. R = 31 mm., 

 r== 10 mm., R = 3 r; breadth of ray at base, 11.5 mm. 



Type.— Cnt. No. 30530, U.S.N.M. 



Type-locality. — Station 5526, between Siquijor and Bohol Islands, 

 Philippine Islands, 805 fathoms, green mud and globigerina; bottom 

 temperature, 52.3° F. 



The paxillar area is compact, and the paxillse are comparatively 

 large, with rather short pedicels crowned by a capitate group of 20 

 to 25 thick clavate or cylindrical, round-tipped, minutely thorny 

 spinelets, about as long as the pedicels, and relatively fewer and 

 thicker than usual in this genus. The superomarginals, 23 in nmnber, 

 are nearly square, abactinal in position, and covered ^dth slightly 

 spaced spinelets similar to those of the paxillse. Inferomarginals 

 corresponding to superomarginals plate for plate, and covered with 

 spaced, appressed, slender, sharp, sometimes flattened and squami- 

 form spinelets, becoming a tuft of longer spinides on the outer end. 

 Two or 3 of these are larger than the rest, arranged in a transverse 

 series, and are similar to the lateral spines of D. sladeni, though less 

 conspicuous. The actinal intermediate plates have fairly liigh ridges 

 crowned by 15 or more slender, very thorny spinelets, larger at the 

 tip than at base, and longer than the inferomarginal spinelets. An 

 odd interradial series of about 4 plates extends from the pair of inter- 

 mediate plates^back of the jaws to the margin. 



